(1) Field of the Invention
The present invention relates to novel multi-substituted 4-acid or alkyl ester or amide imidazolines and to a process for their preparation. In particular the present invention relates to the multi-substituted imidazolines containing a 4-acid or an ester group which inhibit NFκB or NFκB kinase, are anti-inflammatory and/or antimicrobial and/or chemopotentiator and/or chemosensitizers of anticancer agents.
(2) Description of Related Art
Chronic airway inflammation as seen with asthma, is associated with the over expression of inflammatory proteins called cytokines. In addition, other inflammatory mediators, such as IL-1 and TNF, play a major role in joint diseases such as rheumatoid arthritis. All of these inflammatory proteins are highly regulated by the nuclear transcription factor kappa B (NF-κB) (Yamamoto, Y., et al., J. Clin Invest 107 135-142 (2001); and Hart, L. A., et al., Am J Respir Crit Care Med 158 1585-1592 (1998)). Inhibition of this regulatory protein or its kinase by anti-inflammatory drugs has been shown to be effective in the treatment of these diseases (Yamamoto, Y., et al., J. Clin Invest 107 135-142 (2001); Coward, W. R., et al., Clin Exp Allergy 28 Suppl 3, 42-46 (1998); Badger, A. M., et al., J. Pharmacol Exp Ther 290 587-593 (1999); Breton, J. J., et al., J Pharmacol Exp Ther 282 459-466 (1997); Roshak, A., et al., J Pharmacol Exp Ther 283 955-961 (1997); Kopp, E., et al., Science 265 956-959 (1994); Ichiyama, T., et al., Brain Res 911 56-61 (2001); Hehner, S. P., et al., J Immunol 163 5617-5623 (1999); Natarajan, K., et al., Proc Natl Acad Sci USA 93 9090-9095 (1996); and Fung-Leung, W. P., et al., Transplantation 60 362-368 (1995)). The common anti-inflammatory agent, aspirin, and aspirin-like drugs, the salicylates, are widely prescribed agents to treat inflammation and their effectiveness has been attributed to NF-κB inhibition. However, in order to treat chronic inflammations, the cellular levels of these salicylates need to be at very high concentration and are generally prescribed at 1-3 miliMolar plasma concentrations (Science 265, 956-959 (1994)).
Since the discovery of penicillin, over 100 antibacterial agents have been developed to combat a wide variety of bacterial infections. Today, the clinically used antibacterial agents mainly consists of β-lactams (penicillins, carbapenems and cephalosporins), aminoglycosides, tetracyclines, sulfonamides, macrolides (erythromycin), quinolones, and the drug of last resort: vancomycin (a glycopeptide). In recent years, many new strains of bacteria have developed resistance to these drugs throughout the world. There is a need for new antimicrobials.
There is considerable interest in modulating the efficacy of currently used antiproliferative agents to increase the rates and duration of antitumor effects associated with conventional antineoplastic agents. Conventional antiproliferative agents used in the treatment of cancer are broadly grouped as chemical compounds which (1) affect the integrity of nucleic acid polymers by binding, alkylating, inducing strand breaks, intercalating between base pairs or affecting enzymes which maintain the integrity and function of DNA and RNA; and (2) chemical agents that bind to proteins to inhibit enzymatic action (e.g. antimetabolites) or the function of structural proteins necessary for cellular integrity (e.g. antitubulin agents). Other chemical compounds that have been identified to be useful in the treatment of some cancers include drugs which block steroid hormone action for the treatment of breast and prostate cancer, photochemically activated agents, radiation sensitizers and protectors.
Of special interest to this invention are those compounds that directly affect the integrity of the genetic structure of the cancer cells. Nucleic acid polymers such as DNA and RNA are prime targets for anticancer drugs. Alkylating agents such as nitrogen mustards, nitrosoureas, aziridine (such as mitomycin C) containing compounds directly attack DNA. Metal coordination compounds such as cisplatin and carboplatin similarly directly attack the nucleic acid structure resulting in lesions that are difficult for the cells to repair, which, in turn, can result in cell death. Other nucleic acid affecting compounds include anthracycline molecules such as doxorubicin, which intercalates between the nucleic acid base pairs of DNA polymers, bleomycin which causes nucleic acid strand breaks, fraudulent nucleosides such as pyrimidine and purine nucleoside analogs which are inappropriately incorporated into nucleic polymer structures and ultimately cause premature DNA chain termination. Certain enzymes that affect the integrity and functionality of the genome can also be inhibited in cancer cells by specific chemical agents and result in cancer cell death. These include enzymes that affect ribonucleotide reductase (.e.g. hydroxyurea, gemcitabine), topoisomerase I (e.g. camptothecin) and topoisomerase II (e.g. etoposide).
The topoisomerase enzymes affect the structure of supercoiled DNA, because most of the functions of DNA require untwisting. Topoisomerase I (top 1) untwists supercoiled DNA, breaking only one of the two strands, whereas topoisomerase II (top 2) breaks both.
Topoisomerase I inhibition has become important in cancer chemotherapy through the finding that camptothecin (CPT), an alkaloid of plant origin, is the best known inhibitor of top 1 and is a very potent anticancer agent. CPT is contained in a Chinese tree, Camptotheca acuminata. A number of analogs have become approved for commercial use to treat a number of tumor types. These include CPT-11 (irinotecan) and topotecan.
While the clinical activity of camptothecins against a number of types of cancers are demonstratable, improvements in tumor response rates, duration of response and ultimately patient survival are still sought. The invention described herein demonstrates the novel use which can potentiate the antitumor effects of chemotherapeutic drugs, including topoisomerase I inhibitors, in particular, camptothecins.
Relevant Literature
Cancer Chemotherapeutic Agents, W. O. Foye, ed., (ACS, Washington, D.C.) (1995)); Cancer Chemotherapy Handbook, R. T. Dorr and D. D. VonHoff, (Appleton and Lange, Norwalk, Conn.) (1994); and M. P. Boland, Biochemical Society Transactions (2001) volume 29, part 6, p 674-678. DNA damage signaling and NF-κB: implications for survival and death in mammalian cells.
Invasive infection with Gram positive or Gram negative bacteria often results in septic shock and death. Invasion of the blood stream by both types of bacteria (Gram positive and Gram negative) causes sepsis syndrome in humans as a result of an endotoxin, Lipopolysaccharide (LPS) (H. Bohrer, J. Clin. Invest. 972-985 (1997)), that triggers a massive inflammation response in the host. The mechanism by which LPS caused septic shock is through the activation of the transcription factor NF-κB. Activation of this protein by its kinase initiates the massive release of cytokines resulting in a potentially fatal septic shock. For example, the pneumococcus bacteria is the leading cause of death with a mortality rate of 40% in otherwise healthy elderly individuals and staphylococcal infections are the major cause of bacteremia in US hospitals today. Septic shock, caused by an exaggerated host response to these endotoxins often leads to multiple organ dysfunction, multiple organ failure, and remains the leading cause of death in trauma patients.
NF-κB has been indicated to inhibit apoptosis (programmed cell death). Many clinically used chemotherapeutic agents (including the vinca alkaloids, vincristine and vinblastinc, camptothecin and many others) have recently been shown to activate NF-κB resulting in a retardation of their cytotoxicity. This form of resistance is commonly referred to as NF-κB mediated chemoresistance. Inhibition of NF-κB has shown to increase the sensitivity to chemotherapeutic agents of tumor cells and solid tumors.